mbskeam wrote:SIDE FIRING DRIVERS:Hi, this is Bob Carver checking in. There was a question asked that I found very intriguing - intriguing because the problems that arose from my side firing drivers were very challenging to solve. They were so difficult that at one point in the design, I swore that it was a big blunder and that if ever I wanted to do it again and if I were a dictator, I'd hang myself by my toes and give myself a zillion lashes with an expensive interconnect.

Here's my thinking:The side firing drivers began with a conversation I had long ago with Henry Kloss up in Boston one winter while I was visiting good friends. He taught me that our sense of acoustic space lives in about an octave on each side of the octave centered on about 400 Hz. These have become known as the Henry Kloss psyciacoustic octaves. 200 to 800 Hz. He said if we get these octaves right, we will have a beautiful and believable sound stage.Then I read Harry Pearson's treatise on the making of a great sound stage, and I knew I wanted mine to follow HIS teachings. Now Harry did not know how to do it to make it happen in terms of speaker design, though he could describe its beauty like no other journalist in the world. I read what he wrote and could hear it in my head as plain as day. I was hooked forever on a sound stage that had front-to-back depth and emotional envelopment. Just like Harry described. From Henry Kloss's teachings and the sound-picture in my head, I suddenly knew how to do it.

Enter side firing drivers:Use side firing drivers to engage the room, bounce sound off the walls of the room and deliver time-delayed reflections and allow the room to become part of the speakers.All the while keeping their output centered on The Henry Kloss Psychoacoustic Octave. This makes a big space, a large acoustic within which to fit pin-point imaging provided by my ribbon. The ribbon puts the sound images inside the larger acoustic that has been built by the side firing drivers.

So far so good, but a problem came up that was so intractable I thought I'd never solve it short of asking the universe's help. Or at least not solvable by any rational method. The problem was with the time delay associated with the delay of the sound getting around the cabinet to meet the ribbon wave launch, causing a phase-shift related "comb-filter" effect. A phase correction filter done passively turns out to be huge, fully four times as big as the speaker itself! Not practical. I worked on the problem for about a yearand finally hit on the solution so simple I could not believe I did not think of it before. It turns out that the interarual time delay of our heads is about 800 usecs, the same as the time delay from the acoustic center of the side firing drivers to the ribbon wave launch surface. 800 usecs. At this point the solution fell into my lap. Design the crossover to have a large overlap and to allow the natural delays in the music to help generate a larger acoustic by allowing our brain to use those delays and build a big acoustic space. And no combing! What luck! I felt really lucky. That's why I use side firing drivers. Bob Carver

guys and gals, these speakers are truely great. as bob does his thing to have them singing his song, we all await until the bob father says" listen to this" . it is really a major undertaking to built such majesty. so after bob dails them with them in for the cabin enviorment(highly reflective wood and glass) you will start to get some reviews. there will be no wine before bob say's it's time....cheers, and i really " wish you were here"

mbskeam wrote:SIDE FIRING DRIVERS:Hi, this is Bob Carver checking in. There was a question asked that I found very intriguing - intriguing because the problems that arose from my side firing drivers were very challenging to solve. They were so difficult that at one point in the design, I swore that it was a big blunder and that if ever I wanted to do it again and if I were a dictator, I'd hang myself by my toes and give myself a zillion lashes with an expensive interconnect.

Here's my thinking:The side firing drivers began with a conversation I had long ago with Henry Kloss up in Boston one winter while I was visiting good friends. He taught me that our sense of acoustic space lives in about an octave on each side of the octave centered on about 400 Hz. These have become known as the Henry Kloss psyciacoustic octaves. 200 to 800 Hz. He said if we get these octaves right, we will have a beautiful and believable sound stage.Then I read Harry Pearson's treatise on the making of a great sound stage, and I knew I wanted mine to follow HIS teachings. Now Harry did not know how to do it to make it happen in terms of speaker design, though he could describe its beauty like no other journalist in the world. I read what he wrote and could hear it in my head as plain as day. I was hooked forever on a sound stage that had front-to-back depth and emotional envelopment. Just like Harry described. From Henry Kloss's teachings and the sound-picture in my head, I suddenly knew how to do it.

Enter side firing drivers:Use side firing drivers to engage the room, bounce sound off the walls of the room and deliver time-delayed reflections and allow the room to become part of the speakers.All the while keeping their output centered on The Henry Kloss Psychoacoustic Octave. This makes a big space, a large acoustic within which to fit pin-point imaging provided by my ribbon. The ribbon puts the sound images inside the larger acoustic that has been built by the side firing drivers.

So far so good, but a problem came up that was so intractable I thought I'd never solve it short of asking the universe's help. Or at least not solvable by any rational method. The problem was with the time delay associated with the delay of the sound getting around the cabinet to meet the ribbon wave launch, causing a phase-shift related "comb-filter" effect. A phase correction filter done passively turns out to be huge, fully four times as big as the speaker itself! Not practical. I worked on the problem for about a yearand finally hit on the solution so simple I could not believe I did not think of it before. It turns out that the interarual time delay of our heads is about 800 usecs, the same as the time delay from the acoustic center of the side firing drivers to the ribbon wave launch surface. 800 usecs. At this point the solution fell into my lap. Design the crossover to have a large overlap and to allow the natural delays in the music to help generate a larger acoustic by allowing our brain to use those delays and build a big acoustic space. And no combing! What luck! I felt really lucky. That's why I use side firing drivers. Bob Carver

Very Interesting and over my head with much of it. Bottom line, Bob C. thinks outside of the box once again. Wouldn't expect anything else from him based on his past designs/patents.

Was going to ask him why the side/angled back firing woofers myself at Carverfest when most, if not all of the other line arrays I have seen have forward facing woofers.

Can't wait to get my ears around these.

"Side firing drivers" seems to be a good thing.It kinda lays waste to the normal wave diagrams though.On the porch here I once had 5 speakers doing 2 channel stereo.Two in front, 2 behind, and one right over head, plus a sub.This was not home theater stuff.I could control the volume on each set to blend them.All were with in 6 feet of my ears, and it sounded - great, kinda like headphones.

Tom called it lobing or lobbing, I forget.Anyway, to get with the program, changed it all out when Gary told me about the CRS-3.

Now it seems like while different from "side firing drivers", they still bounced the music around and it all was very good.

As most know, the big thing in many speakers now is "radiators". The theory is that they pick up the sound from the real speaker and pass it on.It seems to me that like on the new Carver speaker, better would just be to put in all real speakers. I guess that does drive up the cost though.

OconeeOrange wrote:As most know, the big thing in many speakers now is "radiators". The theory is that they pick up the sound from the real speaker and pass it on.It seems to me that like on the new Carver speaker, better would just be to put in all real speakers. I guess that does drive up the cost though.

Passive radiators. They pick up the energy from the back side opf other drivers & feed iit out.

I never gave them too much thought until I heard Jesse's Polks. They had (I think) six 6" mid/woofers & a 12" passive radiator. It was the first time I'd heard the SDA set up & it really impressed me. Very solid, deep bass & very wide soundstages.

Bill check out the polks there & we'll talk about them when I get there.

OconeeOrange wrote:As most know, the big thing in many speakers now is "radiators". The theory is that they pick up the sound from the real speaker and pass it on.It seems to me that like on the new Carver speaker, better would just be to put in all real speakers. I guess that does drive up the cost though.

Passive radiators. They pick up the energy from the back side opf other drivers & feed iit out.

I never gave them too much thought until I heard Jesse's Polks. They had (I think) six 6" mid/woofers & a 12" passive radiator. It was the first time I'd heard the SDA set up & it really impressed me. Very solid, deep bass & very wide soundstages.

Bill check out the polks there & we'll talk about them when I get there.

I'm counting in hours until the airport.

I have some of the radiators. They are in my 2 Polk subs, and my Def Tec mains and sub. They sound great.Here is an interesting sub that uses opposite firing speakers http://www.epiksubwoofers.com/empire.htmlAt some point if I don't see these some place to listen to, will to have to buy them just from curiosity, and I don't even care much about bass.

The AK moderators just pissed me off.They closed the thread again.Who runs that place? John Atkinson?There's clearly a massive amount of interest in the speakers because Bob's involved personally in the thread.Maybe they're pissed that Bob's cleverly using their forum as a conduit for promotion without actually promoting them.Kinda like he used Stereophile to tweak the Amazings.Man, he's clever.

Martin1970 wrote:The AK moderators just pissed me off.They closed the thread again.Who runs that place? John Atkinson?There's clearly a massive amount of interest in the speakers because Bob's involved personally in the thread.Maybe they're pissed that Bob's cleverly using their forum as a conduit for promotion without actually promoting them.Kinda like he used Stereophile to tweak the Amazings.

Martin1970 wrote:The AK moderators just pissed me off.They closed the thread again.Who runs that place? John Atkinson?There's clearly a massive amount of interest in the speakers because Bob's involved personally in the thread.Maybe they're pissed that Bob's cleverly using their forum as a conduit for promotion without actually promoting them.Kinda like he used Stereophile to tweak the Amazings.

mbskeam wrote:SIDE FIRING DRIVERS: It turns out that the interarual time delay of our heads is about 800 usecs, the same as the time delay from the acoustic center of the side firing drivers to the ribbon wave launch surface. 800 usecs. At this point the solution fell into my lap. Design the crossover to have a large overlap and to allow the natural delays in the music to help generate a larger acoustic by allowing our brain to use those delays and build a big acoustic space. And no combing! What luck! I felt really lucky. That's why I use side firing drivers. Bob Carver

Overlap the frequencies of the tweeters and drivers and lets the listeners brain take care of the rest. I was wondering if that would be a good idea (Overlapping the various speaker frequencies with a crossover not the brain part). If I understand correctly any time delay between the tweeter and mid driver sound wave fronts of 800 usec or less will not be consciously perceivable to the listener. It seems to me that as the delay grows from 0 to 800 usec the listener’s perception of the soundstage size will grow accordingly. If I’m wrong please let me know.

That's to the current page two. Many posts have been "cleaned up" as folks were getting a little hot under the collar~

Here's the last post:

Originally Posted by mbskeam: hi my name is mike beam, I'm at carverfest with Bob,Bob cant seam to log on. so he is using my log in, so I will let him take the wheel from here......

I'm pissed at you Mr Moderator. I cannot believe you deleted a lot of fun and interesting conversation. My reading is that you personally did not like what was said. Please put it back up. Bob Carver

Please read our rules before posting.

As per the rules, only one person may have one account. No others may use it. Comments on moderation are to be taken up via PM and not voiced in the boards. Our rules are the same for everyone. I am going to lock this thread. If Mr. Carver posts under your account again, you will forfeit your account.

Thank youGrumpy

What a dick. So I sent Grumpy this PM:Grumpy,

I just wanted to let you know I think this is a load of horseshit. Ban me if you want, I don't really care if this is the way you run things here.

That's to the current page two. Many posts have been "cleaned up" as folks were getting a little hot under the collar~

Here's the last post:

Originally Posted by mbskeam: hi my name is mike beam, I'm at carverfest with Bob,Bob cant seam to log on. so he is using my log in, so I will let him take the wheel from here......

I'm pissed at you Mr Moderator. I cannot believe you deleted a lot of fun and interesting conversation. My reading is that you personally did not like what was said. Please put it back up. Bob Carver

Please read our rules before posting.

As per the rules, only one person may have one account. No others may use it. Comments on moderation are to be taken up via PM and not voiced in the boards. Our rules are the same for everyone. I am going to lock this thread. If Mr. Carver posts under your account again, you will forfeit your account.

Thank youGrumpy

What a dick. So I sent Grumpy this PM:Grumpy,

I just wanted to let you know I think this is a load of horseshit. Ban me if you want, I don't really care if this is the way you run things here.

Gary GoreTNRabbit

Any chance Mr. Grumpy used to work for Stereophile?

To argue with a person who has renounced the use of reason is like administering medicine to the dead. — Thomas Paine

"Try not to become a man of success, but rather a man of value" Albert Einstein

"Politicians are the only people in the world who create problems and then campaign against them". Charlie Reese

"The problems we face today exist because the people who work for a living are outnumbered by those who vote for a living." Brad Shurett

"Kindness is a language that the Deaf can hear and the Blind can see." Mark Twain